Re: How can I solve thiss error : "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index" - C# Discussion Boards

Re: How can I solve thiss error : "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"

11-Sep-13 1:33

I don't know where I made mistake.I checked everything !! but this error happened :
"Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"

thank you in advance.

int i = 1;
int RowNo = 0;
int CellNo = 0;


foreach (DataGridViewRow row in Firstdgv.Rows)
{

    foreach (DataGridViewCell cell in row.Cells)
    {
        if (i > Finaldgv.Columns.Count)
            break;
        Finaldgv.Rows[RowNo].Cells[CellNo].Value = cell.Value;
        i++;
        CellNo++;

    }
    RowNo++;
    i = 1;
    CellNo = 0;
}

OriginalGriff11-Sep-13 2:31

OriginalGriff

11-Sep-13 2:31

At a guess - and that's about it it can be from that little code - you haven't allocated any rows or columns in the destination DGV, or you are trying to access different sized DGVs.
So when you try to access it's Rows collection via an index:

Finaldgv.Rows[RowNo]

Or the resulting DataGridViewRow Cells collection:

Finaldgv.Rows[RowNo].Cells[CellNo]

It complains becasue it doesn't exist.

Start this way: put a breakpoint on the if line, and single step through from there - look at the variables as you go, and look for null values. (It may help to "break out" the line assigning the row so that each part to the left of a "." is a separate variable - you don't need to, but it makes it easier to see without complex use of the debugger)

DataGridViewRow row = Finaldgv.Rows[RowNo];
DateGridViewCell cell = row.Cells[CellNo];

And so forth.

PS: Keep an eye on the value of i...

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Re: How can I solve thiss error : "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"

Keith Barrow11-Sep-13 2:40

Keith Barrow

11-Sep-13 2:40

First, the value of i isn't doing anything according to your code, you should be able to remove it and use CellNo instead. Personally I'd move the declaration of CellNo inside the first foreach loop, that way you can also remove the line CellNo = 0; at the end.

int RowNo = 0;

foreach (DataGridViewRow row in Firstdgv.Rows)
{
    int CellNo = 0;
    foreach (DataGridViewCell cell in row.Cells)
    {
        if (CellNo >= Finaldgv.Columns.Count)
            break;
        Finaldgv.Rows[RowNo].Cells[CellNo].Value = cell.Value;
        CellNo++;                  
    }
    RowNo++;
}

If this doesn't fix your problem (I doubt it will) you need to figure out which of the two indexes is wrong - you can put a breakpoint on, or you could temporarily amend Finaldgv.Rows[RowNo].Cells[CellNo].Value = cell.Value; to:

var tempRow = Finaldgv.Rows[RowNo]
var tempCell = tempRow.Cells[CellNo]
tempCell.Value = cell.Value

And see which line breaks - my initial gut reaction is you have no rows.

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Re: How can I solve thiss error : "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"

babak1411-Sep-13 5:27

Re: How can I solve thiss error : "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"

11-Sep-13 5:27

my dear friend ,at first I am so appriciate for your attention.
I revised the code as you said but the error still exist !! Frown | :(

the error happens in the "***" line
when the RowNo=1 error occurs !!

// int i = 1;
                   int RowNo = 0;
                   //int CellNo = 0;


                   foreach (DataGridViewRow row in Firstdgv.Rows)
                   {
                       int CellNo = 0;
                       foreach (DataGridViewCell cell in row.Cells)
                       {
                           if (CellNo >= Finaldgv.Columns.Count)
                               break;
                           var tempRow = Finaldgv.Rows[RowNo]; ***
                           var tempCell = tempRow.Cells[CellNo];
                           tempCell.Value = cell.Value;
                           //Finaldgv.Rows[RowNo].Cells[CellNo].Value = cell.Value;
                           //i++;
                           CellNo++;

                       }
                       RowNo++;
                       //i = 1;
                       //CellNo = 0;
                   }

Pete O'Hanlon11-Sep-13 5:38

Re: How can I solve thiss error : "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"

11-Sep-13 5:38

When you put a break point on var tempRow..., and inspect the value, what do you find? The thing that stands out to me here is that you have an assumption that Finaldgv has more than one row, and there's no guarantee that this is the case.

Chill _Maxxx_

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

babak1411-Sep-13 5:53

Re: How can I solve thiss error : "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"

11-Sep-13 5:53

I want to copy Firstdgv rows to Finaldgv rows.So how can I refer to the second,third and... rows in Finaldgv in order to copy the second ,third and .... Firstdgv rows .
I think your assumption is right.but what should I do?

Pete O'Hanlon11-Sep-13 6:31

Re: How can I solve thiss error : "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"

11-Sep-13 6:31

If you are trying to copy the values from one grid into another (and I'm assuming the second one is empty), then you Add the rows into the other grid.

Chill _Maxxx_

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

babak1411-Sep-13 7:25

Re: How can I solve thiss error : "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"

11-Sep-13 7:25

thank you my friend Smile | :)

it works

thank you ALL Wink | ;)

Pete O'Hanlon11-Sep-13 7:55

11-Sep-13 7:55

You're welcome. I'm glad I could be of service.

Chill _Maxxx_

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

reading table from csv

Member 1026649411-Sep-13 0:17

Re: reading table from csv

11-Sep-13 0:17

<pre lang="css">using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


namespace ConsoleApplication1
{
    public class Building
    {

           // csv File contains :


            //Id    X   Y
            //0 91  57
            //1 67  24
            //2 27  27
            //3 97  56
            //4 25  19
            //5 95  18
            //6 5   69
            //7 46  94
            //8 29  68
            //9 92  28


            int[] list1  = new int[3] { 0, 91, 57 };
            int[] list2  = new int[3] { 1, 67, 24 };
            int[] list3  = new int[3] { 2, 27, 27 };
            int[] list4  = new int[3] { 3, 97, 56 };
            int[] list5  = new int[3] { 4, 25, 19 };
            int[] list6  = new int[3] { 5, 95, 18 };
            int[] list7  = new int[3] { 6, 5, 69 };
            int[] list8  = new int[3] { 7, 46, 94 };
            int[] list9  = new int[3] { 8, 29, 68 };
            int[] list10 = new int[3] { 9, 92, 28 };

            //int[][][] lists = new int[][][] { list1, list2, list3, list4, list5, list6, list7, list8, list9, list10 };



           for (int i = 0; i < 4; i++)
            {

                int numberIn = list1[i];
                System.Console.WriteLine(numberIn);

            }


    }
}

I wish to modify this class to allow me to read a csv file in and present an array of arrays that can be returned to a 'stem' class. What is the simplist code that will achieve this please?

Pete O'Hanlon11-Sep-13 3:37

Re: reading table from csv

11-Sep-13 3:37

Seriously, you could solve this part with a simple Google search. You really need to learn how to do that part. I'll give you a couple of hints here:

Your data is in a File. You want to Read All Lines from that file.
Once the data is in lines of strings, you want to Split each string into it's constituent parts.

It's that simple.

Chill _Maxxx_

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Bernhard Hiller11-Sep-13 3:37

Bernhard Hiller

11-Sep-13 3:37

csv stands for comma separated values. The lines below your comment do not show any comma between the values, rather spaces. If all of your values are simple numbers and separated by spaces, just read the file line by line and get the contents with string[] contents = line.Split(' ');, then parse each item of contents into an int (int.Parse(...) or int.TryParse(...)).

working out a triangle hypotenuse

Member 1026649410-Sep-13 23:56

10-Sep-13 23:56

I am looking for my C# class to firstly work out distance between two coordinate points on the x plane and then work out the distance between the same coordinated points on the y plane.

There are potentially several ways of doing this. I was thinking:

Firstly calculate distance on the x plane (x1->x2):

in Excel form:

if (x2 > x1, x2 - x1, x1 - x2)
        (then)   (else)

Then calculate the distance for the y plane (y1->y2):

if (x2 > x1, x2 - x1, x1 - x2)

if we then think of a triangle (with right angle) we have

A(squared) + B(squared) = C(squared)

We would have the length A and B and therefore would be able to calculate C.

Is there an easy way of doing this in C# or is it best to code out the equations?

Any advise appreciated.

Anurag Sinha V11-Sep-13 0:12

Anurag Sinha V

11-Sep-13 0:12

Feels like you need to find out the distance between 2 points on a 2D plane.

Point A (x1,y1)
Point B (x2,y2)

Distance between them would be=[((x1-x2)^2)+((y1-y2)^2)]^(1/2)
Use Math.Abs method to get the absolute value of the distance regardless of x1>x2 or x1

Member 1026649411-Sep-13 0:22

11-Sep-13 0:22

This looks like a good approach. I am really new to C# (after 10 years away), do you have a coded example?

Anurag Sinha V11-Sep-13 0:39

Anurag Sinha V

11-Sep-13 0:39

Its basic maths buddy.. Smile | :)

Let me try to write a simple app for you.

Distance between points (5,5) and the origin (0,0) should be:

public CalculateDistance()
{
double D;
int x1=5;
int x2=0;
int y1=5;
int y2=0;

D=Math.Abs(((x1-x2)^2)+((y1-y2)^2))^(1/2);
Console.WriteLine(D);
Console.ReadKey();
}

The above should do good.
-Anurag

BillWoodruff12-Sep-13 16:33

BillWoodruff

12-Sep-13 16:33

Your question states that what you want is the size of the distance between two x co-ordinates, and the size of the distance between two y co-ordinates, but your code suggests that what you really want is the length of a line between the two points: which is the hypotenuse of a right triangle.

Assuming it's obvious to you how to get the distances on x, and y, and since you already know how to calculate a hypotenuse, then the answer to your question is: no, C# does not contain a built-in function to calculate a hypotenuse. Yes, you have to code it.

And, the real answer to your question is that you need to focus on mastery of the basic mathematics operators in C#, and you need to examine the functions available in the Math library, and get familiar with what it offers, and what it does not offer.

A small effort on your part now to learn the basic mathematics operators, and commonly used functions in the Math library, will enable you to express any equation.

It's a good idea to think carefully about what you are asking, before you post a question.

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Member 1026649410-Sep-13 23:11

10-Sep-13 23:11

I am new to C#. I am not sure whether I am approaching my classes in the right way. I want my main class to act as a stem that activates other classes that performs various tasks like retrieving information or writing to file or performing calculation. I am not sure how to interrelate the classes. I know that some classes have to be public etc.

I was thinking that this stem class would take on the form:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Stem
    {
        static void Main(string[] args)
        {
            // retrieve file name from Main

            // activate 'Building' class (to generate array of coordinates)

            // retrieve array  containing coordinates
            
            //Like:
            //Id	X	Y
            //0	19	75
            //1	76	42
            //2	72	72



            // run through all IDed x,y coordinate combinations and fire off class that performs calculation, one coordinate combination at a time.  Results retrieved and held in array.

            // calls print class at end where output file is produced

        }
    }
}

Firstly I want to know if I am approaching the problem in the right way.

Secondly I would like bits of code that would help me build this stem (if poss).

I would appreciate any help given.

Pete O'Hanlon10-Sep-13 23:19

10-Sep-13 23:19

Hmmm, I think you need to step back here as it sounds like you're trying to run before you understand the basics of building C# applications. Before you try building your own application, I'd recommend downloading and reading .NET Book Zero[^] by Charles Petzold. It's free, and the samples should help to teach you what you need to know.

Chill _Maxxx_

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Member 1026649411-Sep-13 0:27

11-Sep-13 0:27

I can see that I need to modify my approach. What approach to this would you take? Would you suggest that all the tasks that are on the list act as super-classes of the class that takes the main argument?

Pete O'Hanlon11-Sep-13 1:38

11-Sep-13 1:38

You're asking for a design when the problem isn't clear. That's why I suggest you start by reading the book.

Chill _Maxxx_

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Member 1026649411-Sep-13 1:59